Providing two-way data communications to remote sensors and devices is becoming increasingly critical for a wide range of applications. Cost effective communications to terrestrial and maritime field sensors, and industrial automation and control equipment, for example, has the potential to deliver significant economic and environmental benefits in areas such as environmental monitoring for climate change, water, mining, agriculture, defence and national security.
Many high-value applications have modest data rate requirements (kilobits per second), and can tolerate intermittent communications with latency up to several hours. Frequently such applications involve sensors in very remote areas where terrestrial communication solutions do not exist, are unreliable, are denied or insecure (for example, in a defence context). These constraints often mandate the use of satellite communications. For example, for long range oceanic environmental monitoring for environmental, economic and national security reasons, satellite communications is the only feasible solution for command, control and extraction of sensor data. Often, this information will be sensitive (for economic or national security reasons), and so a secure communication system is required.
Unfortunately, existing commercial satellite services may be designed for other applications. For example, at one end of the scale there are expensive, real-time, broadband services. At the other end, there is one-way communications for very small amounts of data.
Prohibitive cost and technical constraints have limited widespread use of large numbers of remote field sensors. Accordingly, it appears that remote communications are commonly under-utilised, or cumbersome data collection is employed, for example, infrequent manual retrieval through site visits, diminishing the ability to collect critical data.
There is thus a need to provide a communications system and method which provides improved communication services for remotely deployed equipment.